Abstract: AIM: To quantify the lactone form and carboxylate form of 10-hydroxycamptothecin (HCPT)in whole blood of dog by develop a simple, rapid, and sensitive high-performance liquid chromatography (HPLC) method.METHODS: The concentration of hydroxycamptothecinum was assayed on a DiscoveryC18 column with a mobile phase consisting of methanol-acetonitriletriethylamine-0. 05 mol·L^-1 dipotassium hydrogen phosphate buffer solution(34 ∶5 ∶1 ∶60, pH =6. 8)at a flow rate of 1. 0 ml·min^-1, and HCPT was monitored with fluorescence detector, excitation and emission wavelengths being 363 nm and 550 nm, respectively.RESULTS: There was a good linear response range of 2. 5-1500 μg·L^-1 while the limit of quantification was 2. 5 μg·L^-1.The relative recovery rate C-HCPT of was 100. 7 %-103. 9 %, L-HCPT of was 96. 8 %-102. 0 %;the absolute recovery rate of C-HCPT was 85. 5 %-98. 6 %, and L-HCPT was 78. 4 %-89. 1 %. The intra-day and inter-day variations were all less than 15 %.The HCPT in supernatant in refrigerator was stable at-75 ℃ for 7 days. CONCLUSSION: The method is simple, sensitive, reliable, and suitable for the quantitative determination of hydroxycamptothecin following i. v. administration, and it is also helpful to improve the study on pharmacokinetics of two active constituents C-HCPT and L-HCPT of HCPT.

Key words: lactone form of 10-hydroxycamptothecin, carboxylate form of 10-hydroxycamptothecin, whole blood, HPLC